Problem 36 - Chemistry and Chemical Reactivity

Question

Element \(109,\) now named meitnerium (in honor of the Austrian-Swedish physicist, Lise Meitner \([1878-1968]\) ), was produced in August 1982 by a team at Germany's Institute for Heavy Ion Research. Depict its electron configuration using spdf and noble gas notations. Name another element found in the same group as meitnerium. (IMAGE CANNOT COPY) Lise Meitner \((1878-1968)\) and Otto Hahn \((1879-1968)\) Element 109 (Mt) was named after Meitner. She earned her Ph.D. in physics under Ludwig Boltzmann at the University of Vienna, and she was the first woman to earn a Ph.D. at that university.

Step-by-Step Solution

Answer

The electron configuration of meitnerium is \\([Rn]7s^2 5f^{14} 6d^7\\). Iridium (Ir) is another element in the same group.

Step 1: Determine the Period and Block

Meitnerium (Mt) is element number 109 in the periodic table. It belongs to period 7 and is part of the d-block, specifically the transition metals. This information helps us understand its position and the general shape of its electron configuration.

Step 2: Identify the Core Electrons Using Noble Gas Notation

The element before meitnerium in the periodic table is radon (Rn), which is a noble gas with the electron configuration \([Rn] = 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^6 5s^2 4d^{10} 5p^6 6s^2 4f^{14} 5d^{10} 6p^6\). We will use radon’s electron configuration as the core in the noble gas notation.

Step 3: Add Electrons Beyond Radon

After radon, the next electrons go into the 7s orbital, then the 5f and 6d orbitals according to the aufbau principle. Using this principle, the electron configuration gets electrons in the following order: \([Rn]7s^2 5f^{14} 6d^7\). This completes the electron configuration for meitnerium.

Step 4: Verify the Electron Configuration

Verify \([Rn]7s^2 5f^{14} 6d^7\) for the correct total of 109 electrons: - Radon has 86 electrons, \- Adding 2 electrons to the 7s orbital gives us 88, \- 14 electrons in the 5f orbital totals 102, \- 7 electrons in the 6d orbital complete the 109 electrons.

Step 5: Identify an Element in the Same Group

Meitnerium is in Group 9 of the periodic table. Other elements in this group include cobalt (Co), rhodium (Rh), and iridium (Ir). Any of these elements can be mentioned as another element in the same group as meitnerium.

Key Concepts

Periodic Table

The periodic table is a structured arrangement of all known chemical elements. Organized by increasing atomic number, which reflects the number of protons in an atom's nucleus, the elements display periodic trends in their properties.
Each period is a horizontal row in the table and indicates the number of electron shells an element possesses. Meitnerium (Mt), for example, resides in the 7th period, indicating it has 7 electron shells as part of its atomic structure.
A group, on the other hand, is a vertical column. Elements within the same group share similar chemical behaviors. Meitnerium is part of Group 9, a group characterized by transition metals which include cobalt (Co), rhodium (Rh), and iridium (Ir). These elements display similarities in their chemical reactions due to having the same number of electrons in their outermost shell.

Electron Configuration

Electron configuration describes the arrangement of electrons within an atom. Electrons occupy orbitals, which are regions around the nucleus with a high probability of finding an electron.
The electron configuration follows a specific order based on the Aufbau principle, pauli-exclusion principle, and Hund's rule. Each electron fills the lowest energy orbital available.

• The notation starts with the lowest energy level, moving up through higher levels as each subshell fills.
• Subshells are indicated as s, p, d, and f, with each holding a specific number of electrons: s (2), p (6), d (10), and f (14).

For meitnerium, its electron configuration ends with the 6d subshell, indicating it's part of the d-block in the periodic table.

Transition Metals

Transition metals are elements found in groups 3 through 12 of the periodic table. They are characterized by having partially filled d orbitals. This gives them unique properties such as:

• The ability to form various oxidation states, allowing them to participate in a wide range of chemical reactions.
• Exhibiting magnetic properties, with metals like iron being well-known for their magnetism.
• Loosely bound electrons in the d orbitals facilitate the formation of alloys with desirable electrical and thermal conductivities.

Meitnerium, being a transition metal in the d-block, shares these properties albeit on an unstable and less commonly observed scale due to its short half-life and synthetic nature.

Noble Gas Notation

Noble gas notation is a shorthand method of writing electron configurations using the electron configuration of the nearest noble gas. This notation starts with the nearest previous noble gas to simplify the presentation and focus on the outermost electrons.
For example, radon (Rn) is used as a reference point in noble gas notation for elements beyond it on the periodic table.

• Noble gases are stable, having full valence electron shells. They are found in the far-right column of the periodic table.
• This notation helps highlight the additional electrons beyond what the noble gas configuration accounts for, making the subsequent electron configuration easier to discern.

In the case of meitnerium, the notation \[ [Rn]7s^2 5f^{14} 6d^7 \] illustrates its complete electron configuration, building on the stable core provided by radon.